[master] + fix one findbugs issue
[master] + return GrizzlyFuture for consistency
[master] + fix improvement #1534
https://java.net/jira/browse/GRIZZLY-1534
"Improve connection.close logging"
[master] + additional update for:
fix improvement #1534
https://java.net/jira/browse/GRIZZLY-1534
"Improve connection.close logging"